MIPS: Allow ASID size to be determined at boot time.

Original patch by Ralf Baechle and removed by Harold Koerfgen
with commit f67e4ffc79905482c3b9b8c8dd65197bac7eb508. This
allows for more generic kernels since the size of the ASID
and corresponding masks can be determined at run-time. This
patch is also required for the new Aptiv cores and has been
tested on Malta and Malta Aptiv platforms.

[ralf@linux-mips.org: Added relevant part of fix
https://patchwork.linux-mips.org/patch/5213/]

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 59 insertions, 36 deletions

diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h
index e81d719efcd1..bab1980bbf0d 100644
--- a/arch/mips/include/asm/mmu_context.h
+++ b/arch/mips/include/asm/mmu_context.h
@@ -62,45 +62,68 @@ extern unsigned long pgd_current[];
 	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)
 #endif
 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT*/
-#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
 
-#define ASID_INC	0x40
-#define ASID_MASK	0xfc0
-
-#elif defined(CONFIG_CPU_R8000)
-
-#define ASID_INC	0x10
-#define ASID_MASK	0xff0
-
-#elif defined(CONFIG_MIPS_MT_SMTC)
-
-#define ASID_INC	0x1
-extern unsigned long smtc_asid_mask;
-#define ASID_MASK	(smtc_asid_mask)
-#define HW_ASID_MASK	0xff
-/* End SMTC/34K debug hack */
-#else /* FIXME: not correct for R6000 */
-
-#define ASID_INC	0x1
-#define ASID_MASK	0xff
+#define ASID_INC(asid)						\
+({								\
+	unsigned long __asid = asid;				\
+	__asm__("1:\taddiu\t%0,1\t\t\t\t# patched\n\t"		\
+	".section\t__asid_inc,\"a\"\n\t"			\
+	".word\t1b\n\t"						\
+	".previous"						\
+	:"=r" (__asid)						\
+	:"0" (__asid));						\
+	__asid;							\
+})
+#define ASID_MASK(asid)						\
+({								\
+	unsigned long __asid = asid;				\
+	__asm__("1:\tandi\t%0,%1,0xfc0\t\t\t# patched\n\t"	\
+	".section\t__asid_mask,\"a\"\n\t"			\
+	".word\t1b\n\t"						\
+	".previous"						\
+	:"=r" (__asid)						\
+	:"r" (__asid));						\
+	__asid;							\
+})
+#define ASID_VERSION_MASK					\
+({								\
+	unsigned long __asid;					\
+	__asm__("1:\taddiu\t%0,$0,0xff00\t\t\t\t# patched\n\t"	\
+	".section\t__asid_version_mask,\"a\"\n\t"		\
+	".word\t1b\n\t"						\
+	".previous"						\
+	:"=r" (__asid));					\
+	__asid;							\
+})
+#define ASID_FIRST_VERSION					\
+({								\
+	unsigned long __asid = asid;				\
+	__asm__("1:\tli\t%0,0x100\t\t\t\t# patched\n\t"		\
+	".section\t__asid_first_version,\"a\"\n\t"		\
+	".word\t1b\n\t"						\
+	".previous"						\
+	:"=r" (__asid));					\
+	__asid;							\
+})
+
+#define ASID_FIRST_VERSION_R3000	0x1000
+#define ASID_FIRST_VERSION_R4000	0x100
+#define ASID_FIRST_VERSION_R8000	0x1000
+#define ASID_FIRST_VERSION_RM9000	0x1000
 
+#ifdef CONFIG_MIPS_MT_SMTC
+#define SMTC_HW_ASID_MASK		0xff
+extern unsigned int smtc_asid_mask;
 #endif
 
 #define cpu_context(cpu, mm)	((mm)->context.asid[cpu])
-#define cpu_asid(cpu, mm)	(cpu_context((cpu), (mm)) & ASID_MASK)
+#define cpu_asid(cpu, mm)	ASID_MASK(cpu_context((cpu), (mm)))
 #define asid_cache(cpu)		(cpu_data[cpu].asid_cache)
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
 }
 
-/*
- *  All unused by hardware upper bits will be considered
- *  as a software asid extension.
- */
-#define ASID_VERSION_MASK  ((unsigned long)~(ASID_MASK|(ASID_MASK-1)))
-#define ASID_FIRST_VERSION ((unsigned long)(~ASID_VERSION_MASK) + 1)
-
 #ifndef CONFIG_MIPS_MT_SMTC
 /* Normal, classic MIPS get_new_mmu_context */
 static inline void
@@ -108,7 +131,7 @@ get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
 {
 	unsigned long asid = asid_cache(cpu);
 
-	if (! ((asid += ASID_INC) & ASID_MASK) ) {
+	if (!ASID_MASK((asid = ASID_INC(asid)))) {
 		if (cpu_has_vtag_icache)
 			flush_icache_all();
 		local_flush_tlb_all();	/* start new asid cycle */
@@ -166,7 +189,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	 * free up the ASID value for use and flush any old
 	 * instances of it from the TLB.
 	 */
-	oldasid = (read_c0_entryhi() & ASID_MASK);
+	oldasid = ASID_MASK(read_c0_entryhi());
 	if(smtc_live_asid[mytlb][oldasid]) {
 		smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
 		if(smtc_live_asid[mytlb][oldasid] == 0)
@@ -177,7 +200,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	 * having ASID_MASK smaller than the hardware maximum,
 	 * make sure no "soft" bits become "hard"...
 	 */
-	write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) |
+	write_c0_entryhi((read_c0_entryhi() & ~SMTC_HW_ASID_MASK) |
 			 cpu_asid(cpu, next));
 	ehb(); /* Make sure it propagates to TCStatus */
 	evpe(mtflags);
@@ -230,15 +253,15 @@ activate_mm(struct mm_struct *prev, struct mm_struct *next)
 #ifdef CONFIG_MIPS_MT_SMTC
 	/* See comments for similar code above */
 	mtflags = dvpe();
-	oldasid = read_c0_entryhi() & ASID_MASK;
+	oldasid = ASID_MASK(read_c0_entryhi());
 	if(smtc_live_asid[mytlb][oldasid]) {
 		smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
 		if(smtc_live_asid[mytlb][oldasid] == 0)
 			 smtc_flush_tlb_asid(oldasid);
 	}
 	/* See comments for similar code above */
-	write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK) |
-			 cpu_asid(cpu, next));
+	write_c0_entryhi((read_c0_entryhi() & ~SMTC_HW_ASID_MASK) |
+	                 cpu_asid(cpu, next));
 	ehb(); /* Make sure it propagates to TCStatus */
 	evpe(mtflags);
 #else
@@ -275,14 +298,14 @@ drop_mmu_context(struct mm_struct *mm, unsigned cpu)
 #ifdef CONFIG_MIPS_MT_SMTC
 		/* See comments for similar code above */
 		prevvpe = dvpe();
-		oldasid = (read_c0_entryhi() & ASID_MASK);
+		oldasid = ASID_MASK(read_c0_entryhi());
 		if (smtc_live_asid[mytlb][oldasid]) {
 			smtc_live_asid[mytlb][oldasid] &= ~(0x1 << cpu);
 			if(smtc_live_asid[mytlb][oldasid] == 0)
 				smtc_flush_tlb_asid(oldasid);
 		}
 		/* See comments for similar code above */
-		write_c0_entryhi((read_c0_entryhi() & ~HW_ASID_MASK)
+		write_c0_entryhi((read_c0_entryhi() & ~SMTC_HW_ASID_MASK)
 				| cpu_asid(cpu, mm));
 		ehb(); /* Make sure it propagates to TCStatus */
 		evpe(prevvpe);